there's no denying that a properly sized a/w setup with ice will get you sub ambient air intake temps, which is a no-brainer for a track car, but i don't see the practicality on a street car.
for the guys running a/w setups on the street feel free to share some data as i'm all ears... go out and cruise around for 30 minutes on a 70 degree plus day, make some pulls on the highway and then post some data such as...
air intake temp
water temp of a/w (before and after temps would be great)
few different points, which people seem to ignore at times...
SIZING: sorry to be blunt but high percentage of turbo guys can't read a compressor maps and can't size their own turbo, so how are they going to size the needed cooling load. copying one persons setup is not ideal, and like someone else mentioned above everyone's needs/application/setups are different.
WEIGHT: intercooler and cold side piping between the two systems is pretty much a wash, but you do have the added weight of the tank, pump, water lines, heat exchanger and fittings. let's not forget the water, which will be 11 gallons (using 10 gallon tank, 1" hose, tank in the trunk, 12' to front of the car, another 12' back), so in all another 11 gallons of water at 8.34lb/pound gives you an added 91 pounds in water. 5 gallon tank would be less, but still nearly 50 pounds in water alone.
PACKAGING: your 750hp car will probably have the battery in the trunk so negative and positive cables running under the car. aftermarket fuel system to support that power means over-sized feed and return lines running running under the car. and now additional feed and return hoses for the water. suppose you could run it through the interior though. also, if i'm not mistaken the engine bays on the older cars are even smaller than foxes and with twin turbos things do get hotter in the engine bay.
ice melts and if you're out cruising around with incorrectly sized system your water will heat soak, so in all don't see the value of it on the street. if an a/a is not enough you can always run water-methanol injection with the a/a to lower the air intake temps plus get the bonus of essentially race gas. that's what i'm running on my 700rwhp car (gotta go back to the dyno and crank up the boost as it should make low 800s). and before someone says that my water-methanol injection pump can fail or system can malfunction my pro-m efi has built in flow meter to handle any failures (snow also has safe injection).